This invention relates to a method and a device for bending a component made of a thermoplastic material, particularly a sleeve-shaped component for a personal care appliance such as a dental care apparatus or the like, by heating the component up to the plastic's softening point.
Plastic injection molding methods are conventionally used for the manufacture of large quantities of plastic components. These methods enable components of straightforward geometrical design to be manufactured with relative ease and at low cost. It is difficult and impractical or uneconomical, however, to use the known injection molding methods for the manufacture of geometrically elaborate components with several openings, undercuts or miniature dimensions, for example. An alternative way to manufacture such plastic components formed to an elaborate geometrical shape is to assemble them from several individual parts, each of which is injection-molded separately in a prior operation. However, this manufacturing approach is not only highly complex but also cost-intensive, particularly where large quantities are involved, hence the need to find an alternative to the multistage manufacturing method for the production of bent sleeve-shaped plastic parts, for example.
Methods and devices for the production and in particular the bending of a plastic component are known in the art. Thus EP 0 464 345 A2 discloses a method and a device for the forming of tubular workpieces made of thermoplastic materials in a mold by the action of heat. This method is characterized in that the amount of heat required for the forming is transferred only to the workpiece to be formed from the inside, and that the workpiece is heated up to the plastic's softening point. The temperature is maintained at this level until the workpiece adopts the shape dictated by a mold, following which the workpiece remains in the mold until it cools.